Clonable Error in Rust

error.rs

use std::sync::Arc;

#[derive(Clone, Debug)]
pub enum Error {
    pub kind: Arc<ErrorKind>,
}

impl std::error::Error for Error {
    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
        match *self.kind {
            // Return the external error as source
            ErrorKind::IO(ref err) => Some(err),
            
            // All native errors to this crate have no external source, hence return None
            ErrorKind::InvalidInput(_) => None  
        }
    }
}

impl std::fmt::Display for Error {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.kind.fmt(f)
    }
}

impl From<ErrorKind> for Error {
    fn from(kind: ErrorKind) -> Error {
        Error{kind: Arc::new(kind)}
    }
}

//----------------------------------------------------------
// ErrorKind ...
//----------------------------------------------------------


pub enum ErrorKind {
    IO(std::io::Error),  // Example of wrapping an external error
    InvalidInput(String), // Error native to *this* crate
}

impl std::fmt::Display for ErrorKind {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            ErrorKind::IO(err) => write!(f, "{}", err),
            ErrorKind::InvalidInput(input) => write!(f, "Invalid input: {}", input)
        }
    }
}

impl std::fmt::Debug for ErrorKind {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.write_str(&format!("{}", self))
    }
}

// Convert std::io::Error to Error
impl From<std::io::Error> for Error {
    fn from(err: std::io::Error) -> Error {
        Error{kind: Arc::new(ErrorKind::IO(err))}
    }
}